PIC16LC923-04/PT Microchip Technology, PIC16LC923-04/PT Datasheet - Page 30

• Manufacturer Part Number: PIC16LC923-04/PT
• Description: IC MCU OTP 4KX14 LCD DVR 64TQFP
• Manufacturer: Microchip Technology
• Series: PIC® 16Cr

Specifications of PIC16LC923-04/PT

• Core Processor: PIC
• Core Size: 8-Bit
• Speed: 4MHz
• Connectivity: I²C, SPI
• Peripherals: LCD, POR, PWM, WDT
• Number Of I /o: 25
• Program Memory Size: 7KB (4K x 14)
• Program Memory Type: OTP
• Ram Size: 176 x 8
• Voltage - Supply (vcc/vdd): 2.5 V ~ 6 V
• Oscillator Type: External
• Operating Temperature: 0°C ~ 70°C
• Package / Case: 64-TFQFP
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Eeprom Size: -
• Data Converters: -

PIC16C9XX
Example 4-1 shows the calling of a subroutine in
page 1 of the program memory. This example assumes
that PCLATH is saved and restored by the interrupt ser-
vice routine (if interrupts are used).
EXAMPLE 4-1:
ORG 0x500
BSF
CALL
ORG 0x900
SUB1_P1:
RETURN
FIGURE 4-10: DIRECT/INDIRECT ADDRESSING
DS30444E - page 30
bank select
RP1:RP0
For memory map detail see Figure 4-2.
PCLATH,3
SUB1_P1
:
:
:
:
:
location select
6
Direct Addressing
Data
Memory
CALL OF A SUBROUTINE IN
PAGE 1 FROM PAGE 0
;Select page 1 (800h-FFFh)
;Call subroutine in
;page 1 (800h-FFFh)
;called subroutine
;page 1 (800h-FFFh)
;return to Call subroutine
;in page 0 (000h-7FFh)
from opcode
7Fh
00h
Bank 0
00
0
Bank 1
01
Bank 2
10
4.5
The INDF register is not a physical register. Addressing
the INDF register will cause indirect addressing.
Indirect addressing is possible by using the INDF reg-
ister. Any instruction using the INDF register actually
accesses the register pointed to by the File Select Reg-
ister (FSR). Reading the INDF register itself indirectly
(FSR = '0') will produce 00h. Writing to the INDF regis-
ter indirectly results in a no-operation (although status
bits may be affected). An effective 9-bit address is
obtained by concatenating the 8-bit FSR register and
the IRP bit (STATUS<7>), as shown in Figure 4-10.
A simple program to clear RAM locations 20h-2Fh
using indirect addressing is shown in Example 4-2.
EXAMPLE 4-2:
NEXT
CONTINUE
Bank 3
11
Indirect Addressing, INDF and FSR
Registers
movlw
movwf
clrf
incf
btfss
goto
:
IRP
bank select
00h
7Fh
0x20
FSR
INDF
FSR,F
FSR,4
NEXT
INDIRECT ADDRESSING
7
Indirect Addressing
1997 Microchip Technology Inc.
;initialize pointer
;to RAM
;clear INDF register
;inc pointer
;all done?
;no clear next
;yes continue
FSR register
location select
0